Image display devices (organic electroluminescent (EL) displays) using organic EL devices (e.g., organic light emitting diodes; OLEDs) are, for example, known as display devices. The organic EL displays are receiving attention as candidates for the next-generation flat panel displays (FPDs) because of their advantages of having good viewing angle characteristics and consuming less power.
There is a phenomenon in which the light emission luminance of light-emitting devices such as organic EL devices for the same voltage decreases due to deterioration over time after long-term use. In view of this, the display devices including light-emitting devices introduce techniques for suppressing a decrease in luminance or suppressing burn-in by controlling a driving voltage in an image signal processing circuit that uses display history information for each pixel or for each display area (see PTL 1, for example).
According to the technique disclosed in PTL 1, a threshold-value (Vth) compensation circuit is formed in the pixels of a display device to suppress variations in the characteristics of driving transistors and thereby to suppress unevenness in luminance for each pixel or for each display area, which may be caused by a decrease in the luminance of light-emitting devices and burn-in.